Analysis Summary
Notes:
- 1) No attempt has been made to eliminate the non-significant decimal places.
- 2) This batgrbproduct analysis is done using the HEASARC data.
- 3) This batgrbproduct analysis is using the flight position for the mask-weighting calculation.
======================================================================
BAT GRB EVENT DATA PROCESSING REPORT
Process Script Ver: batgrbproduct v2.46
Process Start Time: Thu Mar 17 18:56:23 EDT 2016
Host Name: bat1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger671231
======================================================================
Trigger: 00671231 Segment: 000
BAT Trigger Time: 475077053.44 [s; MET]
Trigger Stop: 475077054.464 [s; MET]
UTC: 2016-01-21T13:50:37.710700 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 109.079402870934 Dec: -23.578027813169 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.25
Image Trigger?: NO
Rate S/N Ratio: 10.0498756211209 [ if not an image trigger ]
Image S/N Ratio: 7.25
Analysis Position: [ source = BAT ]
RA: 109.079402870934 Dec: -23.578027813169 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 109.079812152495 Dec: -23.5893503749617 [deg; J2000]
{ 07h 16m 19.2s , -23d 35' 21.7" }
+/- 1.17275275416007 [arcmin] (estimated 90% radius based on SNR)
+/- 0.411298150496529 [arcmin] (formal 1-sigma fit error)
SNR: 24.2243429542839
Angular difference between the analysis and refined position is 0.679726 arcmin
Partial Coding Fraction: 0.9140625 [ including projection effects ]
Duration
T90: 10.4999999403954 +/- 2.39561683996151
Measured from: 0.523999989032745
to: 11.0239999294281 [s; relative to TRIGTIME]
T50: 4.30399996042252 +/- 0.967803687827393
Measured from: 2.55199998617172
to: 6.85599994659424 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 2.75999999046326
to: 3.75999999046326 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.0279999971389771
to: 14.972000002861 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.348553 0.427871 0.258776 0.067168
0.026279 0.027357 0.022702 0.018452 [error]
Peak 0.046871 0.061395 0.029918 0.008352
0.007109 0.007479 0.006098 0.005095 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 15.000 -0.028 14.972
T90 10.500 0.524 11.024
T50 4.304 2.552 6.856
Peak 1.000 2.760 3.760
====== Spectral Analysis Summary =====================================
Model : spectral model: simple power-law (PL) and cutoff power-law (CPL)
Ph_index : photon index: E^{Ph_index}
Ph_90err : 90% error of the photon index
Epeak : Epeak in keV
Epeak_90err: 90% error of Epeak
Norm : normalization at 50 keV in both the PL model and CPL model
Nomr_90err : 90% error of the normalization
chi2 : Chi-Squared
dof : degree of freedo
=== Time-averaged spectral analysis ===
(Best model with acceptable fit: PL)
Model Ph_index Ph_90err_low Ph_90err_hi Epeak Epeak_90err_low Epeak_90err_hi Norm Nomr_90err_low Norm_90err_hi chi2 dof
PL -1.773 -0.131 0.129 - - - 4.43e-03 -3.64e-04 3.60e-04 46.640 57
CPL -1.046 -0.549 0.629 59.583 -11.261 44.854 1.10e-02 -5.39e-03 1.30e-02 41.350 56
=== 1-s peak spectral analysis ===
(Best model with acceptable fit: PL)
Model Ph_index Ph_90err_low Ph_90err_hi Epeak Epeak_90err_low Epeak_90err_hi Norm Nomr_90err_low Norm_90err_hi chi2 dof
PL -1.820 -0.258 0.244 - - - 8.47e-03 -1.47e-03 1.43e-03 56.250 57
CPL -0.929 -1.008 1.369 51.480 -15.341 -51.480 2.74e-02 -2.74e-02 1.41e-01 54.160 56
=== Fluence/Peak Flux Summary ===
Model Band1 Band2 Band3 Band4 Band5 Total
15-25 25-50 50-100 100-350 15-150 15-350 keV
Fluence PL 1.10e-07 1.71e-07 2.00e-07 4.52e-07 6.13e-07 9.32e-07 erg/cm2
90%_error_low -1.23e-08 -1.26e-08 -2.19e-08 -9.36e-08 -5.15e-08 -1.16e-07 erg/cm2
90%_error_hi 1.26e-08 1.26e-08 2.20e-08 1.09e-07 5.20e-08 1.28e-07 erg/cm2
Peak flux PL 4.74e-01 3.95e-01 2.24e-01 1.88e-01 1.18e+00 1.28e+00 ph/cm2/s
90%_error_low -9.73e-02 -5.76e-02 -4.93e-02 -6.87e-02 -1.72e-01 -1.90e-01 ph/cm2/s
90%_error_hi 1.01e-01 5.76e-02 4.97e-02 8.88e-02 1.72e-01 1.91e-01 ph/cm2/s
Fluence CPL 1.00e-07 1.85e-07 2.01e-07 1.55e-07 5.75e-07 6.42e-07 erg/cm2
90%_error_low -1.43e-08 -1.67e-08 -2.46e-08 -8.00e-08 -5.72e-08 -9.90e-08 erg/cm2
90%_error_hi 1.44e-08 1.71e-08 2.43e-08 1.80e-07 5.85e-08 1.85e-07 erg/cm2
Peak flux CPL 4.36e-01 4.41e-01 2.26e-01 6.41e-02 1.15e+00 1.17e+00 ph/cm2/s
90%_error_low -1.12e-01 -7.87e-02 -5.90e-02 -6.41e-02 -1.74e-01 -1.84e-01 ph/cm2/s
90%_error_hi 1.12e-01 8.35e-02 5.63e-02 1.52e-01 1.74e-01 2.11e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 109.0798 -23.5894 0.0079 22.8322 7.7037 1.0218882 24.224 TRIG_00671231 Foreground time interval of the image: -0.028 11.061 (delta_t = 11.089 [sec]) Background time interval of the image: -239.440 -0.028 (delta_t = 239.412 [sec])
Light Curves
Note: The mask-weighted lightcurves have units of either count/det or counts/sec/det, where a det is 0.4 x 0.4 = 0.16 sq cm.
Full-time range; 1 s binning
Other quick-look light curves:
- 64 ms binning (zoomed)
- 16 ms binning (zoomed)
- 8 ms binning (zoomed)
- 2 ms binning (zoomed)
- SN=5 or 10 s binning (full-time range)
- Raw light curve
Spectra
- 64 ms binning (zoomed)
- 16 ms binning (zoomed)
- 8 ms binning (zoomed)
- 2 ms binning (zoomed)
- SN=5 or 10 s binning (full-time range)
- Raw light curve
Spectra
Notes:
- 1) The fitting includes the systematic errors.
- 2) When the burst includes telescope slew time periods, the fitting uses an average response file made from multiple 5-s response files through out the slew time plus single time preiod for the non-slew times, and weighted by the total counts in the corresponding time period using addrmf. An average response file is needed becuase a spectral fit using the pre-slew DRM will introduce some errors in both a spectral shape and a normalization if the PHA file contains a lot of the slew/post-slew time interval.
- 3) For fits to more complicated models (e.g. a power-law over a cutoff power-law), the BAT team has decided to require a chi-square improvement of more than 6 for each extra dof.
Time averaged spectrum fit using the average DRM
Power-law model
Time interval is from -0.028 sec. to 14.972 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.77266 ( -0.131438 0.12854 ) Norm@50keV : 4.43238E-03 ( -0.000363907 0.000360102 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 46.64 using 59 PHA bins. # Reduced chi-squared = 0.8183 for 57 degrees of freedom # Null hypothesis probability = 8.345749e-01 Photon flux (15-150 keV) in 15 sec: 0.604448 ( -0.045036 0.045072 ) ph/cm2/s Energy fluence (15-150 keV) : 6.1286e-07 ( -5.14609e-08 5.20174e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.028 sec. to 14.972 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.04567 ( -0.549155 0.629082 ) Epeak [keV] : 59.5825 ( -11.261 44.8546 ) Norm@50keV : 1.10122E-02 ( -0.00538645 0.0129789 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 41.35 using 59 PHA bins. # Reduced chi-squared = 0.7383 for 56 degrees of freedom # Null hypothesis probability = 9.283549e-01 Photon flux (15-150 keV) in 15 sec: 0.586432 ( -0.047017 0.047012 ) ph/cm2/s Energy fluence (15-150 keV) : 5.75124e-07 ( -5.71579e-08 5.85432e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 2.760 sec. to 3.760 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.81961 ( -0.258038 0.243769 ) Norm@50keV : 8.46667E-03 ( -0.00146777 0.00143137 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 56.25 using 59 PHA bins. # Reduced chi-squared = 0.9868 for 57 degrees of freedom # Null hypothesis probability = 5.032577e-01 Photon flux (15-150 keV) in 1 sec: 1.17574 ( -0.17157 0.1716 ) ph/cm2/s Energy fluence (15-150 keV) : 7.79094e-08 ( -1.34316e-08 1.37211e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 2.760 sec. to 3.760 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.929266 ( -1.00837 1.36922 ) Epeak [keV] : 51.4799 ( -15.3408 -51.48 ) Norm@50keV : 2.73814E-02 ( -0.0273814 0.141013 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 54.16 using 59 PHA bins. # Reduced chi-squared = 0.9672 for 56 degrees of freedom # Null hypothesis probability = 5.446295e-01 Photon flux (15-150 keV) in 1 sec: 1.15009 ( -0.174238 0.17429 ) ph/cm2/s Energy fluence (15-150 keV) : 7.2124e-08 ( -1.40636e-08 1.5145e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 10.5 sec. Hardness ratio (energy fluence ratio) = 1.17073911944
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 2.805004e-07 S(50-150 keV) = 3.3236e-07
The dash-dotted line and the dashed line traces the fluences calculated from the Band function with Epeak = 15 and 150 keV, respectively. Both lines assume a canonical values of alpha = -1 and beta = -2.5.
Mask shadow pattern
IMX = 4.172220750241890E-01, IMY = -5.643792970956614E-02
Spacecraft aspect plot
Bright source in the pre-burst/pre-slew/post-slew images
Pre-burst image of 15-350 keV band
Time interval of the image: -239.440000 -0.028000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 135.5164 -40.5795 1.1 24.4 -66.3 2.6207 10.4 1.6 Vela X-1 162.5867 11.7878 2.4 41.2 168.7 1.7338 4.9 ------ UNKNOWN 80.1889 -28.9283 2.7 49.2 5.5 1.9781 4.3 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -0.028000 11.060590 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 135.3858 -40.4804 3.8 24.3 -66.1 -0.1515 -3.0 7.9 Vela X-1 109.0798 -23.5893 0.5 22.8 7.7 1.0218 24.2 ------ UNKNOWN 161.4984 -13.4709 2.0 28.5 -152.0 0.2617 5.7 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 73.460610 917.060590 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 135.5243 -40.5478 1.2 27.9 -154.7 5.6172 9.9 0.5 Vela X-1 139.9915 4.2927 3.3 41.0 122.8 7.3291 3.5 ------ UNKNOWN 149.9719 -0.7768 3.6 45.7 137.7 8.3539 3.2 ------ UNKNOWN 67.1889 11.0802 3.1 53.6 17.1 9.0261 3.7 ------ UNKNOWN 123.0665 -14.4070 3.9 16.1 129.3 1.6720 2.9 ------ UNKNOWN 55.0781 -23.4851 3.3 49.2 -29.9 4.6834 3.5 ------ UNKNOWN 51.5758 -34.4127 3.7 50.8 -44.6 11.6018 3.1 ------ UNKNOWN 149.2957 -64.4272 4.9 48.5 -130.3 7.3791 2.4 ------ UNKNOWN 112.6749 -66.1815 2.9 42.7 -110.6 11.7687 4.0 ------ UNKNOWN